Toluene → Boc-allo-Ile-OH

HRID 1598535Notes

Reaction equation

HRID 1598535 reaction equation
[NH2:1][C@H:2]([C:7]([OH:9])=[O:8])[C@@H:3]([CH2:5][CH3:6])[CH3:4].[OH-:10].[Na+].[C:12]1([CH3:18])[CH:17]=CC=C[CH:13]=1.[CH3:19][OH:20].O>>[C:19]([NH:1][C@H:2]([C:7]([OH:9])=[O:8])[C@@H:3]([CH2:5][CH3:6])[CH3:4])([O:20][C:12]([CH3:18])([CH3:17])[CH3:13])=[O:10]

Participants

5

Reactant 4

HCID 1140TolueneHCID 14798Sodium Hydroxide2×HCID 99288Alloisoleucine, DL-HCID 22242641Methanol--water (1/1)

Product 1

HCID 6992549Boc-allo-Ile-OH

Conditions

Temperature
10 °C

Procedure

L-allo-isoleucine (20.0 gm, 0.152 mole) was suspended in 200 ml of 50% MeOH/H2O. The pH was adjusted to 9-9.5 with 4N NaOH. The reaction mixture was cooled to 10° C. and di-tert butoxydicarbonate (39.8 gm, 0.184 mole) was added. The pH was maintained at 9-9.5 with NaOH. After about 0.5 hour, the cooling bath was removed. The reaction mixture was stirred at room temperature for 3-4 hours. TLC in 5% MeOH/CH2 Cl2 was taken. When the reaction was complete, the reaction mixture was acidified to pH 3 with 20% citric acid, extracted with 3×500 mL of CH2Cl2, dried over MgSO4, filtered and evaporated to give a gum. 200 mL of toluene were added and the reaction mixture was evaporated. This last step was repeated two more times to obtain a gum which was dried under high vacuum for 2 days to give a solid (37.53 gm).

Workup

  1. customthe cooling bath was removed
  2. extractionextracted with 3×500 mL of CH2Cl2
  3. dry with materialdried over MgSO4
  4. filtrationfiltered
  5. customevaporated
  6. customto give a gum
  7. customthe reaction mixture was evaporated
  8. customto obtain a gum which
  9. customwas dried under high vacuum for 2 days

Sources & evidence

ORD record
ord-1e93df76f4c34602b0351a843bfb7334
Source dataset
uspto-grants-1998_04
Patent number
US05739104

Reaction notes

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